1. Field Of The Invention
The present invention relates to the field of heat removal systems for electrical devices. Specifically, the present invention relates to heat removal systems for semiconductor devices and the like.
2. Description of Related Art
The traditional method for cooling electric devices has been through convection. Using this method, heat is dissipated from an electric device through the outer surfaces of the device into still air or an airflow driven by a fan. In some cases, special heat sink devices have been fitted to the electric devices to provide a more efficient mechanism for dissipating heat from the device using convection. One such heat sink is disclosed in U.S. Pat. No. 5,168,926, entitled "Heat Sink Design Integrating Interface Material", assigned to Intel Corporation. The heat sink described in this patent comprises a flat surface which is bonded directly to a flat surface on a semiconductor device. This heat sink also comprises a plurality of fins extending above the flat surface of the semiconductor device. The plurality of fins substantially increase the surface area of the heat sink thereby increasing the heat dissipation characteristics of the heat sink. Heat generated by the semiconductor device is transferred through an adhesive bonding agent into the heat sink where the heat is effectively dispersed.
As the integration level (i.e., the number of electrical primitives or transistors per device) of electric devices increases, or the power requirements or the operating speed of electric devices increases, the amount of heat generated by these devices increases to a point where conventional air convection solutions are inadequate. Conventional air convection solutions are inadequate because airflow requirements necessary to dissipate the greater level of heat become excessive or the physical size of the heat sink required to dissipate the heat becomes prohibitive. The physical size of a heat sink is a particular problem for compact form factors such as notebook computers.
Other conventional heat dissipation systems include solid state refrigeration systems using the Peltier effect to remove heat. These "heat pump" systems create more heat than they remove thereby contributing to the ultimate thermal problem. Moreover, these systems require considerable electrical power.
Other heat dissipation systems use miniature fans coupled to the fins of a conventional heat sink device. These miniature fans increase the thermal efficiency of a conventional heat sink by increasing the airflow through the heat sink. These fans however, consume additional electrical power, contribute additional audible noise to the system, and increase system failures because of moving parts in the fan.
Thus, a more efficient means for removing heat from heat generating electrical devices is needed.